Foundry casting material composition

ABSTRACT

A foundry core material comprising a foundry sand, a binder, and a disintegration additive, where the material is treated to form a solid component of a casting mold. The present invention also provides methods of forming casting materials.

INTRODUCTION

The present invention relates to a composition and method of usingfoundry casting materials for improved removal after casting.

In the foundry industry, one of the procedures used for making metalparts is by casting. Casting materials are arranged to create anassembly forming a mold or receptacle having an empty cavity that can befilled with a molten metal. Typically, such a cavity is defined by anouter mold boundary (a boundary defining a surface perimeter or spatiallimit of the mold shape) formed by an outer shell mold, and further, bycores that may optionally be placed within the interior of the cavityfor additional interior surface contours defined by inner moldboundaries. As referred to herein, “mold” refers to any mold componentincluding a core or shell that is formed from casting material thatforms a cast part. Cores are solid components that provide hollowinternal elements within a cast metal part, without necessitating theneed for additional machining or boring. Shells form the exteriorcomponents of the mold cavity. Any remaining empty spaces within thecavity form the shape of a part, having both the inner and outersurfaces once the molten metal solidifies. After molten metal is pouredinto the assembly of molds and cores, it is left to cool and form ametal part which is subsequently removed from the assembly.

Different portions of the mold may be sacrificial, meaning that the moldis only used once in the casting process and then destroyed aftercasting the part. Generally, sacrificial components include the innercores, and sometimes the outer shell molds. Such an example of the outershells being sacrificed is in investment casting, where the entire shellmold is destroyed. Further contemplated are shells where layers thatcontact the metal surface are often sacrificed, and then the shell isreconstituted with another new external replacement layer.

Casting materials also contain a binder system, typically comprising abinder material and a compatible solvent suspension system for holdingthe foundry sand within a solid matrix. When a mixture of castingmaterials is formed, it must be further treated to solidify the castingmaterial, which is generally achieved by cross-linking or curing thebinder in the matrix. Specific binder materials dictate the type oftreatment necessary to solidify the structural mold. No-bake, cold-box,and hot-box all refer to the types of treatment necessary forsolidification. Hot-box treatment includes pre-heating (e.g. fromtemperatures ranging from about 40° C. to about 260° C.) the castingmaterial mixture with a thermosetting binder for to cure or set.Cold-box treatment is where curing is typically achieved by a vapor orgas catalyst passed through the casting material mixture, which inducescuring, sometimes conducted at slightly elevated temperatures (e.g. fromabout 35° C. to about 100° C.) to ensure vaporization of the catalyst.The casting material mixture is shaped by putting it into a pattern andallowing it to cure until it is self-supporting and can be handled. Ano-bake system cures without any baking (i.e. at ambient temperatures)where a catalyst is added directly to the casting material mixture.Usually, a no-bake catalyst is admixed with the casting material mixtureand then formed into a shaped mold where it subsequently sets up as asolid.

After the metal has cooled within the casting material assembly, theexterior mold is readily removed. However, the casting material coresthat remain on the inside of the cast part are difficult to remove.Known methods of removing such cores include immersing the steel castinginto a bath of molten salt at elevated temperatures (e.g., about 500°C.) for many hours. Often, after removing the part from the molten bath,casting material still adheres to the surface of the metal part, andmust be removed by physical means such as blasting, chipping, ordrilling the debris away by hand. Such removal methods are frequentlydangerous and inefficient.

Recently, attempts have been made to remove the remaining castingmaterials by immersing the cast part (with cores present) into anelectrolytic bath, where an anode is submerged into an electrolyte andthe surface of the part forms the cathode. Hydrogen gas bubbles areformed at the surface of the metal part, which are thought to assist inremoving adherent casting materials. However, it has been found thatelectrolytic activity and hydrogen bubble formation may not be effectivein removing casting materials from the metal part. Thus, there is a needfor easy and efficient removal of a sacrificial casting materialremaining within or on a cast part, preferably by electrolyticprocessing.

SUMMARY

The present invention provides foundry casting materials for use inmaking a mold for a cast part, comprising a foundry sand, a binder, anda disintegration additive. In various embodiments, the present inventionprovides a foundry mold formed for the casting of a part, comprising amixture of a foundry sand, a binder, and a disintegration additive,where the mixture is treated to form a solid.

According to the present invention, methods of forming a metal part areprovided. Such a method comprises pouring molten metal into a mold,where the mold is formed of a material comprising foundry sand, binder,and a disintegration additive. The molten metal is cooled to form asolid, and the solid is removed from the mold.

Further embodiments according to the present invention include a methodof removing residual casting material from a metal part, where themethod comprises the steps of: attaching the metal part having residualcasting material to a power source having a first and a second electrodeof opposite polarities, wherein the first electrode is attached to themetal part. The metal part is contacted with an electrolyte that is incontact with the second electrode. Current is generated through theelectrolyte, from the first electrode to the second electrode. Theresidual casting material is made from a mixture comprising castingsand, binder and a disintegration additive.

Further areas of applicability of the present invention will becomeapparent from the detailed description provided hereinafter. It shouldbe understood that the detailed description and specific examples, whileindicating specific embodiments of the invention, are intended forpurposes of illustration only and are not intended to limit the scope ofthe invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts an exemplary apparatus useful in a cleaning method ofthis invention.

FIG. 2 depicts a second exemplary apparatus useful in a cleaning methodof this invention.

It should be noted that the apparatus depicted in FIGS. 1 and 2 areintended to show the general characteristics of apparatus and methodsamong those of this invention, for the purpose of the description ofsuch embodiments herein. These figures may not precisely reflect thecharacteristics of any given embodiment, and are not necessarilyintended to define or limit specific embodiments within the scope ofthis invention.

DESCRIPTION

The present invention provides a disintegration additive for a castingmaterial that facilitates enhanced removal of any residual castingmaterial remaining on or in a cast part. The foundry casting material isformed into at least a portion of a mold, preferably a sacrificialportion of the mold (e.g. shell, core, or both) remaining within or on acast part after the casting is completed. The foundry casting materialcomprises a foundry sand, a binder, and a disintegration additive. Incertain embodiments, the foundry casting material is treated to form asolid foundry mold. One embodiment of the present invention includes amethod of removing any residual casting material from a metal part byattaching the metal part having residual casting material to oneelectrode of a power source having electrodes of opposite polarities andcontacting the metal part with an electrolyte, accomplishingelectrolytic processing. (As used herein, the word “include,” and itsvariants, is intended to be non-limiting, such that recitation of itemsin a list is not to the exclusion of other like items that may also beuseful in the materials, compositions, devices, and methods of thisinvention. Also, as used herein, the words “preferred” and “preferably”refer to embodiments of the invention that afford certain benefits,under certain circumstances. However, other embodiments may also bepreferred, under the same or other circumstances. Furthermore, therecitation of one or more preferred embodiments does not imply thatother embodiments are not useful and is not intended to exclude otherembodiments from the scope of the invention.

Based upon the large variety of casting applications, foundry castingmolds (e.g. cores and shells) may be constructed of the same ordifferent materials. Selection of casting materials used for the shellmolds depends upon various factors, including the physical and chemicalproperties of the metals to be cast. The melting point of the metal ormetal alloy dictates temperature and strength requirements of the mold.Other factors in casting material selection include: the intricacy ofthe shape being cast, finish needed, and tolerance for flaws anddefects.

Conventional casting materials typically contain an aggregate, such as aconventional foundry sand, generally being either bank or syntheticsands. Bank sands are naturally occurring and usually containcontaminants (e.g. clay). Synthetic sands (e.g. lake sands or sharpsands) are formed with a base sand grain, which is typically silica, butmay also be zircon, olivine, or chromite. Sand selection in a castingmaterial is dependent on the application. Various physical and chemicalproperties (including grain size and distribution) effect interactionwith the binder material and specific metals being cast. A castingmaterial may further include mixtures of different sands, including bothsynthetic and bank sands.

Further, casting materials contain a binder which can be no-bake,cold-box, or hot-box, as previously discussed. A phenolic urethanebinder is preferred for both the no-bake and cold-box processes. Thedifference in the curing method of phenolic urethane binder originatesfrom the different solvents (or binder system) in which the binder isdispersed. In a no-bake, a different solvent is used which reacts with aliquid curing catalyst that is mixed with the casting material mixture(including an aggregate and binder system) to form a mold mix. Theliquid catalyst is mixed into the casting material mixture beforeshaping and cures within a short time thereafter (e.g. from about 30minutes to about a few hours later). In a cold-box process, a gaseoustertiary amine curing catalyst (e.g. TEA (tetraethylamine) and DMEA(dimethylethylamine)) is passed through a shaped casting materialmixture containing a phenolic urethane binder (typically consisting of aphenolic resin component and a polyisocyanate component) to cure themixture. Phenolic urethane binders are widely used in the foundryindustry to bond the sand cores used in casting iron and aluminum.

Hot-box fabrication processes use resins that harden the sand when thecasting material is pre-heated to temperatures between from about 35° toabout 300° C.. Such an example of hot-box fabrication includes shellmolding, where the shell is formed from a mixture of sand and athermosetting resin binder that is placed against a heated metalpattern, or template. The heat induces setting of the resin, forming asolid forming at least a portion of the receptacle for receiving moltenmetal and forming a cast metal part. Such resins may include bindersbased upon furan resins and furfuryl alcohols. Typically, such resinsare cured in the presence of a latent acid curing catalyst. Ceramic moldmediums are another example of hot-box treated mold, wherein theinorganic clay components (e.g. aluminum silicate, bentonite, ormontmorillonite) form a binder. They are typically formed by layering alost wax/foam mold with successive layers of a slurry of foundry sandand inorganic binder which are then cured with heat.

The present invention provides a foundry casting material whichcomprises a mixture comprising a foundry sand, a binder, and adisintegration additive. The additive (herein “disintegration additive”)for the casting material compositions facilitates and/or expeditesremoval of any residual casting material from a metal part formed usingthe casting material. Preferably, the disintegration additivefacilitates removal of the casting material by causing the castingmaterial to disintegrate, in whole or in part, by either heating,chemical (or electrochemical) interaction, or use of moderate physicalforce. One such method of applying both electrochemical interaction andmoderate physical force is with an electrolytic cleaning method. By“disintegration”, it is meant that the casting material is broken downinto smaller particulate form, in pieces small enough that the originalsolid form is readily removable from any substrate or hollow on orwithin the cast part. The present invention also provides a foundry moldformed for the casting of a part, comprising a mixture of a foundrysand, a binder, and a disintegration additive, where the mixture istreated to form a solid (e.g. a mold to accept the molten metal).

Selection of disintegration additives to compositions of the presentinvention is dependent on the metal being cast, but generally should notcompromise the characteristics necessary for proper casting, includingsurface finish and tensile strength. The additive preferably does notsignificantly impair structural strength or heat endurance, which couldpotentially induce premature failure during the casting process.Further, the additive is preferably selected for chemical compatibilitywith the binder resin, most particularly with either the polymeric body,side chains, or terminal groups to promote homogeneous distribution toachieve proper curing strengths. Grain size and distribution for anadditive may also be important aspects depending on the metal to becast, to avoid marring or other defects in the surface of the finishedpart. Thus, some of the primary considerations in additive selectioninclude physical and chemical compatibility within the casting materialmatrix and interaction with the metal to be cast. Secondaryconsiderations include selecting a disintegration additive that isavailable on a widespread basis in a large variety of grain sizes andpurity for low cost.

A preferred embodiment of the present invention includes disintegrationadditive compounds that are crystalline solids and have relatively highmelting points (i.e. above 300° C.). In one embodiment, polar moleculesare preferred. In one embodiment, the disintegration additive enhancesthe electron/ion conduction of the casting material when contacted witha polar electrolyte (e.g. water). In various embodiments, disintegrationadditives are selected from a class of salts that volatilize duringcasting of the metal part leaving behind a porous and slightly unstablestructure. In various embodiments, the disintegration additive is chosento facilitate ion mobility within the casting material solid structure,resulting in chemical interaction with an electrolyte that reduceselectrolytic processing time, which sufficiently disintegrates thesolids remaining on the cast part.

One preferred embodiment of the present invention includes adisintegration additive that is a salt. Salts fulfill many of thephysical, chemical, and economic requirements needed for adisintegration additive. Preferred salts selected as additives includesalts that are inorganic and soluble in water, and preferably comprisecations having metals selected from Groups I and II of the PeriodicTable. As referred to herein, “Group” refers to the Group numbers (i.e.,columns) of the Periodic Table as defined in the current IUPAC PeriodicTable. Preferred anions for the salt of the disintegration additivesaccording to the present invention include, carbonates, nitrates,sulfates, phosphates, hydroxides, and halogens. Certain preferred saltsaccording to the present invention comprise cations of sodium,potassium, calcium, ammonium, or magnesium, and include salts, such asfor example: sodium carbonate, sodium bicarbonate, sodium chloride,sodium hydroxide, sodium iodide, sodium nitrate, sodium phosphate,disodium phosphate, sodium sulfate, potassium carbonate, potassiumchloride, potassium hydroxide, potassium iodide, potassium nitrate,potassium phosphate, potassium sulfate, calcium carbonate, calciumchloride, calcium hydroxide, calcium iodide, calcium nitrate, calciumsulfate, ammonium sulfate, ammonium carbonate, magnesium carbonate,magnesium chloride, magnesium hydroxide, magnesium iodide, magnesiumnitrate, magnesium phosphate, magnesium sulfate, and equivalents andmixtures thereof. In a preferred embodiment, the disintegration additiveis selected from the group consisting of sodium chloride, potassiumchloride, sodium carbonate, sodium bicarbonate, sodium phosphate, andmixtures thereof. In a particularly preferred embodiment, thedisintegration additive comprises sodium chloride. In another preferredembodiment, the disintegration additive comprises sodium bicarbonate,disodium phosphate, and mixtures thereof. In another preferredembodiment, the disintegration additive comprises sodium carbonate,disodium phosphate, and mixtures thereof.

One aspect of a preferred embodiment of the present invention relates toa method of making of a mold made from a casting material of thisinvention. Thus, in certain preferred embodiments the present inventionprovides a foundry mold for the casting of a part comprising a mixtureof a foundry sand, a binder, and a disintegration additive, where themixture is treated to form a solid. In one aspect of the presentinvention, the disintegration additive and foundry sand raw materialsmay be pre-mixed to achieve homogeneous distribution, prior to addingthe binder materials. In some casting material molds, the shape of theform is created with the foundry sand and disintegration additive, priorto adding the binder materials. In other preferred embodiments of thepresent invention, the foundry sand, disintegration additive, and bindermaterial are admixed together concurrently to form an admixture andlater shaped. Any mixing of the raw materials is done by conventionalmixing means known to one of skill in the art until the raw materialsare evenly distributed. Examples of such conventional mixing meansinclude: zero-retention high speed continuous mixers, low-speedaugur-type continuous mixers, and batch mixers.

The admixture of casting materials is shaped in any variety of waysknown to one of skill in the art, typically achieved by using a patternin the shape of the portion of the surface of the part to be cast. Thecasting materials surround the pattern and form a contrapositive surfacecontour, or shape, within the casting materials, which creates the moldshape or receptacle which will later hold molten metal. By“contrapositive” it is meant that a first surface has a general shape orcontour and that the first surface interfaces with a second surface andgenerally imprints a matching or opposite contour along the secondsurface where the first and second surface interface. Patterns may befabricated from wood, metal, or other materials, including wax (known asa “lost-wax” process in investment casting), where casting materialscoat the pattern by dipping the wax pattern into a slurry of castingmaterials that forms individual layers. Other variations includedepressing the pattern into a bed of casting material which adopts theshape of the pattern. Many variations of forming casting materials intomolds are known by skilled artisans and are dependent upon the type ofcasting materials used. (e.g. silica sand molds, lost wax ceramic molds,and the like)

Cores are solid pieces formed from casting materials having contouredsurfaces that will form part of the interior shape of the cast part,hence forming inner mold boundaries within the cast part. The surfacesof the cores and molds are contoured to impart a contrapositive surfacecontour onto the molten metal which coats the interior cavities of thecasting mold. Thus, solid components forming the casting mold includeboth the exterior shell molds and the interior cores, and both mayincorporate aspects of the present invention. The mixture is then shapedinto a contoured surface and treated to form a rigid solid having acontoured surface.

After creating the casting mold components, any individual casting moldcomponents are arranged into a mold having an outer mold boundary formedby the outer shell molds which defines the external surface of the castmetal part and an inner boundary formed by the inner shell molds whichcreates internal surfaces of the cast metal part. The empty portions orcavities are then completely filled with enough molten metal to contactall surfaces of the casting mold creating a shaped cast metal part.Typically, a casting mold further contains a sprue, a runner, and ariser to allow for pouring of the molten metal into the empty cavity ofthe casting mold. The sprue receives the incoming molten metal andchannels it below to the casting mold cavity, the runner is region thatconnects the sprue to various areas within the casting mold, and theriser is an additional reservoir that provides extra metal to thecasting mold cavity during solidification when the metal contracts insize. Thus, molten metal is poured into the casting mold and thenpermitted to solidify into the cast metal part. The present invention isparticularly useful for forming industrial parts, which areconventionally formed by metal casting. Manufactured industrial parts,such as cast metallic components, may include, for example, automotivedrive train components (e.g. a combustion engine blocks).

After solidification of the metal, the cast solid part is removed fromthe outer shell. If the casting mold was formed of two shell parts, theyare separated and the cast solid part is easily removed. Generally, theouter shell is readily removed from the cast part after solidification.Sometimes, layers of the outer shell may remain on the cast metalsubstrate, or surface. These layers must be subsequently removed fromthe surface of the cast part. Generally, the difficulty in cleaning acast part arises when removing the inner core components. The innercores remain within the cast part after solidification, and theconventional means of removal include those previously mentioned, theenergy intensive process of submersing the part in a molten salt bath atrelatively high temperatures or by physical removal of the core byblasting, chipping, or sanding away the residual casting material, andusually using both processes.

Thus, the present invention thus provides a method of forming a metalpart, which comprises pouring molten metal into a mold formed of amaterial comprising a foundry sand, a binder, and a disintegrationadditive, then cooling the molten metal to form a solid, and removingthe solid from the mold.

The present invention also provides an alternate preferred embodimentwhere residual casting material is removed from a metal part. The metalpart having residual casting material is attached to a power sourcehaving a first and a second electrode of opposite polarities, where thefirst electrode is attached to the metal part. The metal part iscontacted with an electrolyte, where the electrolyte is in contact withthe second electrode. Current is generated by the power source throughthe electrolyte, from the first electrode and second electrode. In thismanner, a method of electrolytically cleaning the residual material fromthe metal part is provided.

Industrial parts washers among those useful herein comprise, in oneembodiment, one or more processing zones for washing, rinsing, dryingand other steps for cleaning industrial parts. A conveyor typicallytransports the parts through the processing zones from one end of thewasher to the other. Industrial parts washers typically spray the partswith heated liquid cleaners, and thus most washers include an enclosureto capture the spray and contaminants being washed. Certain preferredindustrial parts washers may include a holder to secure and support thepart to be washed. In one embodiment, the holder is suitable for holdingan automotive drive train components. The holder and part are enclosedin a chamber which forms a sealed unit encapsulating the part. A cleanerdispersing system is operable to remove residual materials from thepart. A preferred part washer useful herein is described in U.S. patentapplication Ser. No. ______, “Housingless Part Washer,” Stockert et al.;filed Aug. 21, 2003, incorporated by reference herein.

In one embodiment, the cleaner dispersing system comprises a spraydevice, such as a spray head or nozzle, which is coupled to a cleaningfluid supply. The spray device is positioned within the chamber, suchthat it is operable to contact the part with cleaning fluid. It ispreferred that such a parts washer additionally comprises a fluidrecirculator which collects and recycles spent or used cleaning fluid.The cleaning fluid supply is contained in a cleaning fluid tank, and isconnected to a fluid propulsion device. Such devices include those knownto one of skill in the art, such as a centrifugal pump, where apressurized cleaning fluid supply is delivered to a spray device. Incertain alternate preferred configurations, a parts washer comprises areservoir filled with cleaning fluid which immerses the part on theholder. Such parts washers may further be adapted to incorporateelectrolytic cleaning, where the spray device(s) are connected to apower source with a first electrode having a first polarity, and theholder is connected to a second electrode having a second polarity ofthe same power source. In this manner, the part is charged with oppositepolarity to the spray device. Further, the cleaning fluid becomescharged and operates as an electrolyte.

As shown in FIG. 1, the present invention provides methods for removingany residual casting material from a cast metal part 10 with anelectrolytic processing apparatus 12, by contacting the cast metal part10 having the inner core 22 (intact) with an electrolyte 16. In oneembodiment, the cast metal part 10 is submerged in an electrolyte 16,and serves as a cathode 23. The cast metal part when attached to thenegative lead 26 of a power source 20. At least one anode 18 is attachedto a positive lead 24 of the power source 20 is also placed within theelectrolyte 16. When a voltage is applied by the power source 20,current is generated through the electrolyte 16 between the anode 18 andthe cathode 23.

One aspect of the present invention includes a disintegration additive28 in the casting material inner core 22 that facilitates disintegrationwhen subjected to electrolytic processing. This type of disintegrationadditive preferably promotes electron/ion conduction. Other preferredtypes of disintegration additives include those substances with aboiling point below the temperature of the molten metal, which permitsvolatilization of the salt from the casting material core or mold. Theresulting void spaces create a porous structure that enhancesdisintegration. The disintegration additive may comprise mixtures ofdisintegration additives, each of which facilitate disintegration in adifferent manner. One preferred embodiment of the present invention isan apparatus comprising a holder adapted to secure a cast metal part,and a cleaner dispersing system operable to remove residual castingmaterial from the cast metal part, where the casting material is madeusing a disintegration additive.

In another preferred embodiment, the present invention provides anapparatus comprising a cast part having a surface coated with residualcasting material comprising a disintegration additive, a holder adaptedto secure the cast part, and a fluid tank adapted to contain cleaningfluid for cleaning the cast part. Additionally, the apparatus maycomprise a fluid propulsion device connected to the fluid tank. A spraydevice is connected to the propulsion device which is adapted to applycleaning fluid on a surface of the cast part. The apparatus is operableto remove residual casting material form the metal part. Anotherpreferred embodiment of the present invention provides a system for theproduction of a clean industrial part, comprising a casting materialsuitable for casting a part. The casting material comprises foundrysand, binder, and disintegration additive, where in a portion of thecasting material remains on the part after casting. A parts washer isoperable to contact the cast part with cleaning fluid.

Other preferred embodiments of the present invention include a method ofmaking a clean metal part, comprising casting a metal part using a moldformed using a casting material comprising foundry sand, binder, and adisintegration additive, and cleaning the cast metal part using a partswasher comprising a cleaner dispensing system. In certain preferredembodiments, the parts washer comprises at least one spray deviceoperable to apply cleaning fluid on a surface of the cast metal part.

In one embodiment, the cleaning fluid comprises an electrolyte. Suchelectrolyte cleaning fluids may be formed, for example, by dissolvingdisodium phosphate and sodium bicarbonate in water. The metal parthaving a casting core or residual material on a surface is contactedwith the electrolyte. The remaining casting material comprises foundrysand, binder, and a disintegration additive. The cast metal part isconnected to a negative terminal of a power source and an anode isconnected to a positive terminal of the power source and placed in theelectrolyte. A current is generated through the electrolyte via thepower source to remove the casting core from the cast metal part. Inpreferred embodiments, at least one inner core is removed from theconductive solid by generating current between the anode and conductivesolid through the electrolyte, whereby the inner core at least partiallydisintegrates.

In another embodiment of the present invention, a generalized partswasher is shown in FIG. 2, where a continuous stream or spray 30 ofelectrolyte 16 is sprayed on the cast metal part 10 having an inner core22 (with a disintegration additive 28) from at least one anode 18 (i.e.spray device) which is connected to a positive lead 24 of the powersource 20. The cast metal part 10 is secured by a holder 25 which isconnected to the negative lead 26 of the power source 20 which conductselectricity and forms the cathode 23. Further, the electrolyte spray 30may be directed to residual casting materials 32 left on the surface 34of the cast metal part 10. Such electrolytic action assists indisintegrating the inner core 22 or residual material 32 so that theymay be readily removed to produce a clean cast metal part 10. Variationsof preferred embodiments of the present invention include anodes 18 thatspray electrolyte 16, while submerged in a reservoir of electrolyte, toincrease the electrolytic action.

Preferred electrolytes comprise conductive salts, and may form bothbasic and acidic solutions when dissolved in a solvent, such as water.Salts useful herein include disodium phosphate (Na₂HPO₄), sodiumbicarbonate (NaHCO₃), sodium carbonate (Na₂CO₃), and mixtures thereof.Voltage is applied by a conventional power source, as known to one ofskill in the art, such as for example, a low voltage direct currentsource with 5 to 350 A output from a 60 HZ, 230V, 3 phase alternatingcurrent source. Electrolytic cleaning processes among those usefulherein include those disclosed in U.S. Pat. Nos. 6,203,691 and 6,264,823both to Hoffman, Jr., et al, incorporated herein by reference.

After submerging the conductive part in the electrolyte and applying thepower to generate current, the part is left within the electrolyticprocessing until all of the inner cores erode or disintegrate and areflushed away from the cast part. Such flushing away from the partgenerally occurs from turbulent electrolyte flow, where the particulateis removed from the part. The above process also removes layers ofresidual shell material from the substrate of the cast part, when thecasting material is prepared according to the present invention. Thepieces of particulate that are formed by disintegration of the castingmaterial may be collected from the bottom of the electrolyte containerand recycled to form new casting raw materials, if feasible, aspreviously discussed, in a fluid recirculator.

Thus, one method of removing a casting core includes forming anelectrolyte by dissolving electrolyte salts in water. Then, theelectrolyte contacts the metal part (with the casting core made offoundry sand, binder, and disintegration additive intact). The castmetal part is then connected to a negative terminal of a power source,and further an anode connected to a positive terminal of the powersource is placed in the electrolyte. The power source is activated andgenerates current through the electrolyte to remove the casting corefrom the cast metal part. Thus, variations of this method may be used toform a clean cast metal part.

The embodiments described herein are exemplary and not intended to belimiting in describing the full scope of compositions and methods ofthis invention. Equivalent changes, modifications and variations ofspecific embodiments, materials, compositions and methods may be madewith substantially similar results.

1. A foundry casting material for use in making a mold for a cast part,comprising: (a) foundry sand; (b binder; and (c) a disintegrationadditive.
 2. A foundry casting material according to claim 1, whereinthe material forms a core of the mold.
 3. A foundry casting materialaccording to claim 1, wherein the cast part comprises a metal.
 4. Afoundry casting material according to claim 1, wherein the cast part isan automotive drive train part.
 5. A foundry casting material accordingto claim 1, wherein said disintegration additive enhances electron/ionconduction when the casting material is immersed in water.
 6. A foundrycasting material according to claim 5, wherein said disintegrationadditive is a salt.
 7. A foundry casting material according to Clam 1,wherein said disintegration additive promotes disintegration of thecasting material during an electrolytic cleaning process.
 8. A foundrycasting material according to claim 1, wherein said disintegrationadditive volatilizes during the process of making said part.
 9. Afoundry casting material according to claim 1, wherein saiddisintegration additive is a salt.
 10. A foundry casting materialaccording to claim 9, wherein said salt comprises sodium.
 11. A foundrycasting material according to claim 10, wherein said salt is selectedfrom the group consisting of: sodium chloride, sodium carbonate, sodiumbicarbonate, sodium diphosphate, and mixtures thereof.
 12. A foundrycasting material according to claim 9, wherein said salt comprisespotassium.
 13. A foundry casting material according to claim 9, whereinthe salt comprises carbonate.
 14. A foundry casting material accordingto claim 9, wherein the salt comprises phosphate.
 15. A foundry castingmaterial according to claim 1, wherein said disintegration additive isan electrolyte salt.
 16. A foundry casting material according to claim9, wherein the disintegration additive is selected from the groupconsisting of: sodium carbonate, sodium chloride, sodium hydroxide,sodium iodide, sodium nitrate, sodium phosphate, sodium sulfate,potassium carbonate, potassium chloride, potassium hydroxide, potassiumiodide, potassium nitrate, potassium phosphate, potassium sulfate,calcium carbonate, calcium chloride, calcium hydroxide, calcium iodide,calcium nitrate, calcium sulfate, ammonium sulfate, ammonium carbonate,magnesium carbonate, magnesium chloride, magnesium hydroxide, magnesiumiodide, magnesium nitrate, magnesium phosphate, magnesium sulfate, andmixtures thereof.
 17. A foundry casting material according to claim 1,wherein said foundry sand comprises a synthetic sand.
 18. A foundrycasting material according to claim 1, wherein said foundry sandcomprises a bank sand.
 19. A foundry casting material according to claim1, wherein said foundry sand comprises a silica sand.
 20. A foundrycasting material according to claim 1, wherein said binder comprises aphenolic urethane resin.
 21. A foundry casting material according toclaim 1, wherein said binder comprises a clay.
 22. A foundry mold formedfor the casting of a part, comprising a mixture of: (a) a foundry sand;(b) a binder; and (c) a disintegration additive, wherein said mixture istreated to form a solid.
 23. A foundry mold according to claim 22,wherein said cast part comprises a metal.
 24. A foundry mold accordingto claim 23, wherein said cast part is an automotive drive train part.25. A foundry mold according to claim 22, wherein said disintegrationadditive enhances electron/ion conduction when said casting material isimmersed in water.
 26. A foundry mold according to Clam 22, wherein saiddisintegration additive promotes disintegration of said cast materialduring an electrolytic cleaning process.
 27. A foundry mold according toclaim 22, wherein said disintegration additive volatilizes during theprocess of making said cast.
 28. A foundry mold according to claim 22,wherein said disintegration additive is a salt.
 29. A foundry moldaccording to claim 28, wherein the disintegration additive is selectedfrom the group consisting of: sodium carbonate, sodium chloride, sodiumhydroxide, sodium iodide, sodium nitrate, sodium phosphate, sodiumsulfate, potassium carbonate, potassium chloride, potassium hydroxide,potassium iodide, potassium nitrate, potassium phosphate, potassiumsulfate, calcium carbonate, calcium chloride, calcium hydroxide, calciumiodide, calcium nitrate, calcium sulfate, ammonium sulfate, ammoniumcarbonate, magnesium carbonate, magnesium chloride, magnesium hydroxide,magnesium iodide, magnesium nitrate, magnesium phosphate, magnesiumsulfate, and mixtures thereof.
 30. A foundry mold according to claim 22,wherein said foundry sand comprises a material selected from the groupconsisting of: synthetic sand, bank sand, silica sand, and mixturesthereof.
 31. A foundry mold according to claim 22, wherein said bindercomprises a material selected from the group consisting of: phenolicurethane resin, clay, and mixtures thereof.
 32. A method of forming ametal part comprising: (a) pouring molten metal into a mold, whereinsaid mold is formed of a material comprising foundry sand, binder, and adisintegration additive; (b) cooling said molten metal to form a solid;and (c) removing the solid from said mold.
 33. A method of forming ametal part according to claim 32, wherein said removing step furthercomprises: (i) physically separating said solid from said mold, toexpose a metal part, wherein residual mold material remains on a surfaceof the metal part; (ii) attaching the metal part to a power sourcehaving a first and a second electrode of opposite polarities, whereinsaid first electrode is attached to the metal part; (iii) contacting themetal part with an electrolyte, wherein said electrolyte is in contactwith said second electrode; and (iv) generating current through saidelectrolyte, from said first electrode to said second electrode.
 34. Amethod of forming a metal part according to claim 33, wherein saidelectrolyte comprises a salt selected from the group consisting of:sodium carbonate, sodium bicarbonate, disodium phosphate, and mixturesthereof.
 35. A method of forming a metal part according to claim 34,wherein said salt is sodium carbonate.
 36. A method of forming a metalpart according to claim 33, wherein said first electrode is a cathode.37. A method of forming a metal part according to claim 33, wherein saidcontacting is by immersing said metal part in a reservoir of saidelectrolyte.
 38. A method of forming a metal part according to claim 33,wherein said contacting is by spraying said electrolyte on a surface ofsaid metal part.
 39. A method of forming a metal part according to claim32, wherein said metal part is an automotive drive train part.
 40. Amethod of forming a metal part according to claim 33, wherein saiddisintegration additive enhances electron/ion conduction when saidcasting material is contacted with said electrolyte.
 41. A method offorming a metal part according to Clam 33, wherein said disintegrationadditive promotes disintegration of said cast material during saidremoving step.
 42. A method of forming a metal part according to claim32, wherein said disintegration additive volatilizes during the processof making said cast.
 43. A method of forming a metal part according toclaim 32, wherein said disintegration additive is a salt.
 44. A methodof forming a metal part according to claim 43, wherein thedisintegration additive is selected from the group consisting of: sodiumcarbonate, sodium chloride, sodium hydroxide, sodium iodide, sodiumnitrate, sodium phosphate, sodium sulfate, potassium carbonate,potassium chloride, potassium hydroxide, potassium iodide, potassiumnitrate, potassium phosphate, potassium sulfate, calcium carbonate,calcium chloride, calcium hydroxide, calcium iodide, calcium nitrate,calcium sulfate, ammonium sulfate, ammonium carbonate, magnesiumcarbonate, magnesium chloride, magnesium hydroxide, magnesium iodide,magnesium nitrate, magnesium phosphate, magnesium sulfate, and mixturesthereof.
 45. A method of forming a metal part according to claim 32,wherein said binder comprises a material selected from the groupconsisting of phenolic urethane resin, clay, and mixtures thereof.
 46. Amethod of removing residual casting material from a metal part, themethod comprising the steps of: (a) attaching the metal part havingresidual casting material to a power source having a first and a secondelectrode of opposite polarities, wherein said first electrode isattached to the metal part; (b) contacting said metal part with anelectrolyte, wherein said electrolyte is in contact with said secondelectrode; and (c) generating current through said electrolyte, fromsaid first electrode to said second electrode; wherein said residualcasting material is made from a mixture comprising casting sand, binderand a disintegration additive.
 47. A method of removing residual castingmaterial according to claim 46, wherein said contacting is by immersingsaid metal part in a reservoir of said electrolyte.
 48. A method ofremoving residual casting material according to claim 46, wherein saidcontacting is by spraying said electrolyte on a surface of said metalpart.
 49. A method of removing residual casting material according toclaim 46, wherein said electrolyte comprises a salt selected from thegroup consisting of: sodium carbonate, sodium bicarbonate, disodiumphosphate, and mixtures thereof.
 50. A method of removing residualcasting material according to claim 49, wherein said salt is sodiumcarbonate.
 51. A method of removing residual casting material accordingto claim 46, wherein said first electrode is a cathode.
 52. A method ofremoving residual casting material according to claim 46, wherein saidmetal part is an automotive drive train part.
 53. A method of removingresidual casting material according to claim 46, wherein saiddisintegration additive enhances electron/ion conduction when saidcasting material is contacted with said electrolyte.
 54. A method ofremoving residual casting material according to Clam 46, wherein saiddisintegration additive promotes disintegration of said cast materialduring said removing step.
 55. A method of removing residual castingmaterial according to claim 46, wherein said disintegration additivevolatilizes during the process of making said cast.
 56. A method ofremoving residual casting material according to claim 46, wherein saiddisintegration additive is a salt.
 57. A method of removing residualcasting material according to claim 56, wherein the disintegrationadditive is selected from the group consisting of: sodium carbonate,sodium chloride, sodium hydroxide, sodium iodide, sodium nitrate, sodiumphosphate, sodium sulfate, potassium carbonate, potassium chloride,potassium hydroxide, potassium iodide, potassium nitrate, potassiumphosphate, potassium sulfate, calcium carbonate, calcium chloride,calcium hydroxide, calcium iodide, calcium nitrate, calcium sulfate,ammonium sulfate, ammonium carbonate, magnesium carbonate, magnesiumchloride, magnesium hydroxide, magnesium iodide, magnesium nitrate,magnesium phosphate, magnesium sulfate, and mixtures thereof.
 58. Amethod of removing residual casting material according to claim 46,wherein said foundry sand comprises a material selected from the groupconsisting of synthetic sand, bank sand, silica sand, and mixturesthereof.
 59. A method of removing residual casting material according toclaim 46, wherein said binder comprises a material selected from thegroup consisting of phenolic urethane resin, clay, and mixtures thereof.